RM Poole, circa 1973/4: spectacular demo redolent of the then popular "Kung Fu" TV programme ("Grasshopper" etc). Adolescent self suitably awestruck/ impressed.
Was then told they'd demonstrate how "one undersized but highly trained Marine" would deal with simultaneous attack by four much larger men: cue appearance of said small Marine dressed in baggy smock. Suddenly, from each corner of the gym, 4 HUGE fellows charged, screaming blue murder, waving machetes, clubs etc.! Small Marine drew an Ingram from under smock and gave them a blast; followed by a few "finishing shots" from a sawn-off he also produced from somewhere on his person. Nothing more needed to be said!
The SC1 who was looking after me made a few observations, mainly along the following lines: there's no such thing as a fair fight; he who hits first ( preferably from behind ) wins; and, above all, remember "There's no such thing as the glorious dead." In his opinion, the most effective "martial art" was the ancient Lancastrian fighting system "Ecky Thump" ( at the time popularised by "The Goodies" ) - the only "system" to integrate aforementioned precepts into a coherent package that can be taught to anyone in less than an hour. Nothing I've seen or experienced since has suggested to me that he was anything other than absolutely right.